In tax year 2024 (bills paid in 2025), the Cook County Board of Review cut $5.7 billion of assessed value, 6.4% of the county's total. Taxing districts still collected their levies. The same dollars were spread over a smaller base.
We estimate that added about 2.6% to the bill of a typical house whose value the Board did not lower. At the median, that is $178 on a $6,692 bill.
Most of that shift came from commercial and industrial property, not from neighbors' homes. Cuts on homes, condos and small apartment buildings alone added about 0.7%, or $36.
Quick Answer
Yes, a little. When other owners win reductions, tax rates rise slightly for everyone else, because the levy is spread over a smaller base. For tax year 2024 we estimate the Board of Review's cuts raised the bill of a typical uncut Cook County house by about 2.6%, a median of $178. In Chicago, which was reassessed that year, the estimate was about 7%. Most of the shift came from commercial property. These are approximations built from county records, not official figures. The fix is not to resent appeals. It is to check your own value, because the system assumes you will.
How the shift works
Each taxing district asks for a dollar amount: the levy. The County Clerk turns that into a rate by dividing the levy by the taxable value in the district.
When the Board lowers some values, the levy does not shrink. The rate goes up to collect the same dollars. Owners who won a cut pay less. Everyone else pays a little more.
A rough rule: if a district loses a share r of its taxable value, its rate rises by about r ÷ (1 − r). Lose 6.4% and rates rise about 6.8%, if every levy were spread over that base alone. Real bills move less than that, for reasons covered below.
What the Board removed in tax year 2024
- Decisions: 571,841 parcels had a Board decision, 30.8% of the county's 1,859,067 parcels.
- Value removed: $5.7 billion of $89.1 billion in assessed value, 6.4%.
- Who got it: 76.6% of the removed value was commercial and industrial property. 12.1% was apartment buildings with seven or more units. 10.6% was homes, condos and two- to six-unit buildings.
- City vs. suburbs: Chicago was reassessed for 2024. The Board removed 9.4% of city value, and 42.4% of city parcels had a decision. In the suburbs it removed 2.4%, and 20.3% of parcels had a decision.
By township
Tax year 2024. "Removed" is the Board's cut as a share of the value it started from. The last three columns are for houses the Board did not lower.
| Township | Region | Parcels with a Board decision | Value removed, all property | Value removed, homes and small apartments | Estimated rate effect | Typical bill ($) | Estimated added ($) |
|---|---|---|---|---|---|---|---|
| Hyde Park | City | 17.7% | 6.3% | 1.2% | 7.0% | 1,955 | 127 |
| Jefferson | City | 35.9% | 4.2% | 1.4% | 7.0% | 6,231 | 406 |
| Lake | City | 13.0% | 4.7% | 0.7% | 7.0% | 3,112 | 202 |
| Lake View | City | 73.9% | 5.7% | 2.1% | 7.0% | 18,925 | 1,232 |
| North Chicago | City | 87.9% | 12.3% | 2.0% | 7.0% | 26,534 | 1,729 |
| Rogers Park | City | 56.3% | 6.3% | 1.5% | 7.0% | 7,448 | 485 |
| South Chicago | City | 72.9% | 16.9% | 1.5% | 7.0% | 6,644 | 433 |
| West Chicago | City | 42.5% | 8.9% | 1.8% | 7.0% | 3,974 | 259 |
| Barrington | North | 24.5% | 6.8% | 1.1% | 1.6% | 13,374 | 200 |
| Elk Grove | North | 23.0% | 1.8% | 0.6% | 2.0% | 8,139 | 157 |
| Evanston | North | 27.5% | 1.9% | 0.8% | 2.3% | 11,586 | 258 |
| Hanover | North | 15.2% | 1.3% | 0.4% | 0.9% | 6,887 | 56 |
| Leyden | North | 21.9% | 3.8% | 0.8% | 3.4% | 6,965 | 217 |
| Maine | North | 19.6% | 1.9% | 0.6% | 1.8% | 7,868 | 164 |
| New Trier | North | 37.3% | 1.6% | 1.5% | 2.0% | 19,150 | 374 |
| Niles | North | 25.4% | 2.5% | 0.6% | 2.3% | 8,343 | 182 |
| Northfield | North | 25.2% | 3.0% | 0.8% | 2.8% | 13,177 | 399 |
| Norwood Park | North | 24.4% | 1.2% | 0.7% | 1.7% | 7,438 | 130 |
| Palatine | North | 19.7% | 2.1% | 0.6% | 2.3% | 9,372 | 223 |
| Schaumburg | North | 17.8% | 2.8% | 0.4% | 2.8% | 8,158 | 220 |
| Wheeling | North | 22.7% | 2.1% | 0.6% | 2.2% | 9,392 | 198 |
| Berwyn | South/West | 24.8% | 1.3% | 1.1% | 1.7% | 7,163 | 119 |
| Bloom | South/West | 11.2% | 2.1% | 0.6% | 2.2% | 5,008 | 117 |
| Bremen | South/West | 14.5% | 1.2% | 0.7% | 1.5% | 6,518 | 97 |
| Calumet | South/West | 17.0% | 7.9% | 1.2% | 4.7% | 4,310 | 124 |
| Cicero | South/West | 18.0% | 2.1% | 0.9% | 2.2% | 5,851 | 125 |
| Lemont | South/West | 24.9% | 2.1% | 1.1% | 2.1% | 9,021 | 182 |
| Lyons | South/West | 24.9% | 1.8% | 1.0% | 1.5% | 7,974 | 135 |
| Oak Park | South/West | 28.4% | 3.4% | 1.3% | 3.7% | 13,845 | 496 |
| Orland | South/West | 23.2% | 1.7% | 0.8% | 2.2% | 8,106 | 160 |
| Palos | South/West | 25.1% | 1.6% | 0.9% | 1.9% | 7,801 | 142 |
| Proviso | South/West | 18.2% | 2.3% | 0.7% | 1.7% | 7,071 | 124 |
| Rich | South/West | 17.6% | 1.9% | 0.6% | 1.9% | 8,466 | 143 |
| River Forest | South/West | 31.9% | 1.5% | 1.4% | 2.4% | 18,196 | 418 |
| Riverside | South/West | 24.6% | 1.6% | 1.1% | 1.9% | 9,564 | 171 |
| Stickney | South/West | 16.3% | 3.7% | 0.5% | 3.5% | 6,124 | 194 |
| Thornton | South/West | 14.3% | 4.9% | 0.8% | 2.8% | 5,433 | 138 |
| Worth | South/West | 16.0% | 1.7% | 0.6% | 2.2% | 6,133 | 118 |
"Typical bill" is the median tax year 2024 bill for those houses. "Estimated added" is the median of each house's bill times its estimated rate effect.
Why every city township shows the same 7%
Your bill is made of many taxing districts, and most cross township lines. The city government, the Chicago schools and the park district each cover all eight city townships. The county's own levy covers the whole county.
So North Chicago's 12.3% cut, mostly on commercial and large apartment property, was shared by every city home, not just North Chicago's. The rough rule would put North Chicago at 14%. Spread across the actual districts, it is about 7% for every city township. In the suburbs the estimate can land above or below the rough rule. It depends on which townships each district covers, whether a district reaches into a neighboring county the Cook Board doesn't touch, and how much of the cut fell on TIF parcels.
Why this is an approximation
- TIF districts. Inside a tax increment financing district, a cut usually reduces the TIF's take, not the base other districts tax. We left cuts on TIF parcels out of the base. Counting them would put the city estimate near 12% and the county median near 3.6%.
- Exemptions. Exemptions come off before rates apply. We used each parcel's actual exemptions.
- Assessor-stage cuts. Before the Board, Assessor appeals and corrections lowered values from $91.7 billion as mailed to $89.1 billion. Later refunds through the state appeal board or the Assessor's refund process (it calls it a Certificate of Error) come after. Neither is counted here.
- The state multiplier. We held it at its actual tax year 2024 value, 3.0355. Our guide to the equalization factor explains what it does.
- Levy limits. We assumed every district would collect the same dollars either way. Districts at a rate ceiling may not.
- The source. PTAXSIM, the Cook County Assessor's Office research database. The Assessor says its results are not official.
Treat each number as an estimate, not a bill.
This is not an argument against appeals
An appeal that fixes a wrong value moves the system toward fair. The problem is not that others appeal. It is that the system quietly assumes every owner checks.
If your value is right, you pay your fair share plus a small shift. If your value is too high and you don't appeal, you pay for your own over-assessment and a share of everyone else's cuts. Taxes also rise for reasons that have nothing to do with appeals, such as levies and rates. Our piece on why Cook County property taxes keep rising covers those.
What to do
- Check your value every year, not just in your reassessment year.
- Compare it with recent sales of similar homes nearby.
- Make sure your exemptions are on the bill. Censum's exemption check is free.
- If your value is high, file inside your township's window. County forms are free.
Where Censum fits
On Censum's free appeal check you enter a PIN or address and see appeal odds for your home, built from past Board of Review outcomes on similar homes, plus the appeal window that is open. Saved results get reminder emails when the Assessor and Board windows open. Censum prepares appeal packets if you want help. The Board decides every appeal.
The numbers behind this article
Value removed, bills and rate effects are Censum's calculations from PTAXSIM, the Cook County Assessor's Office research database, version 2024.0.0, run November 11, 2026. "Removed" is the Assessor's certified value minus the Board's value, summed over all parcels, divided by total certified value. For the rate effect we rebuilt each parcel's taxable value with and without its Board cut (value times the state multiplier, 3.0355, minus its exemptions), added the difference to every taxing district the parcel pays, left out parcels inside a TIF, and recomputed each district's rate as its actual levy divided by the larger base. A tax code's effect is its actual total rate divided by the recomputed rate, minus one. "Houses the Board did not lower" are classes 2-02 to 2-10, 2-34, 2-78 and 2-95 whose Board value equaled the certified value and whose bill was above zero: 824,748 of 928,233 houses. Medians are across those houses. The homes-only estimate repeats the calculation using only class 2 cuts. Decision counts come from the Board of Review Appeal Decision History dataset, tax year 2024 (one row per parcel); its total of Board cuts, $5.63 billion, is within 1% of PTAXSIM's $5.67 billion. Class shares group PTAXSIM classes: 2 (homes, condos, two- to six-unit buildings), 3 and 9 (apartments with seven or more units), 5 through 8 (commercial and industrial).
FAQ
Do other people's appeals raise my taxes?
Slightly. When values are cut, the same levies are spread over a smaller base. For tax year 2024 we estimate a median of $178 on a typical uncut Cook County house.
How much of that is from neighbors' homes?
About $36 at the median. Most of the shift came from commercial and industrial property, which made up 76.6% of the value the Board removed.
Why is the effect bigger in Chicago?
Tax year 2024 was Chicago's reassessment year, and the Board removed 9.4% of city value, most of it on commercial and large apartment property. City-wide districts spread that over every city home.
If I appeal and win, do I stop paying for others' cuts?
You still pay the slightly higher rate, but on a lower value, so you come out ahead of not appealing. Your own cut barely moves the rate.
Sources
- PTAXSIM, the Cook County Assessor's Office research database and R package, version 2024.0.0; Censum calculations run November 11, 2026.
- Censum tabulation of the Cook County Board of Review Appeal Decision History dataset (Cook County open data), tax year 2024.
- Cook County Board of Review, Frequently Asked Questions
- Cook County Assessor, Homeowner Exemption (how exemptions and the multiplier enter the bill)
- Cook County Assessor, Assessment and Appeal Calendar
Sources accessed November 11, 2026.
Next step
Find out whether your own value is one worth checking this year. Check my appeal odds
Censum LLC is a data and analytics company, not a law firm and not a tax advisor. Censum is independent and is not affiliated with Cook County or any government agency.